From 2e2fd842ca75c47cfaeb5e618d3795b3fed950cd Mon Sep 17 00:00:00 2001
From: scratko <m@scratko.xyz>
Date: Fri, 21 Jun 2024 16:54:52 +0300
Subject: Initial commit

---
 daemon.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 80 insertions(+)
 create mode 100644 daemon.c

(limited to 'daemon.c')

diff --git a/daemon.c b/daemon.c
new file mode 100644
index 0000000..6bdb46b
--- /dev/null
+++ b/daemon.c
@@ -0,0 +1,80 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <time.h>
+#include <stdlib.h>
+#include <syslog.h>
+
+volatile sig_atomic_t get_info = 0;
+volatile sig_atomic_t signal_counter = 0;
+
+void handler(int s)
+{
+    signal(SIGUSR1, handler);
+    signal(SIGALRM, handler);
+
+    switch(s) {
+    case SIGUSR1:
+        get_info = 1;
+        ++signal_counter;
+        break;
+    case SIGALRM:
+        get_info = 1;
+        alarm(300);
+    }
+}
+
+int main()
+{
+    int fd, pid;
+    char *path = "/tmp/ordinary_daemon.log";
+    FILE *file;
+    time_t start, end;
+    double dif;
+
+    signal(SIGUSR1, handler);
+    signal(SIGALRM, handler);
+    close(0);
+    close(1);
+    close(2);
+    open("/dev/null", O_RDONLY);
+    open("/dev/null", O_WRONLY);
+    open("/dev/null", O_WRONLY);
+    chdir("/");
+    pid = fork();
+    if(pid > 0)
+        exit(0);
+    setsid();
+    pid = fork();
+    if(pid > 0)
+        exit(0);
+    fd = open(path, O_CREAT | O_WRONLY | O_TRUNC, 0666);
+    file = fdopen(fd, "w");
+    if(fd == -1) {
+        perror("can't open file");
+        exit(1);
+    }
+    openlog("ordinary daemon", 0, LOG_USER);
+    syslog(LOG_INFO, "daemon started");
+    alarm(300);
+    pid = getpid();
+    time(&start);
+
+    while(1) {
+        pause();
+        if(get_info) {
+            time(&end);
+            dif = difftime(end, start);
+            fprintf(file, "time spent (in sec): %.2f pid: %u SIGUSR1: %u\n",
+                    dif, pid, signal_counter);
+            syslog(LOG_INFO, "time spent (in sec): %.2f pid: %u SIGUSR1: %u",
+                    dif, pid, signal_counter);
+            fflush(file);
+            get_info = 0;
+        }
+    }
+    closelog();
+    close(fd);
+    return 0;
+}
-- 
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